1. Technical Field
The present disclosure relates to a pixel structure. More particularly, the present disclosure relates to a pixel structure in an electrophoretic display.
2. Description of Related Art
For a conventional skill of manufacturing an electrophoretic display (also called electronic paper), during a fabrication process of a lower substrate, there are usually a silicon nitride (SiNx) dielectric layer and a thicker organic transparent layer formed between a thin-film transistor and a pixel electrode, such that on the lower substrate the pixel electrode can thus stride over the thin-film transistor without resulting in the increase of stray capacitance and affecting the electricity of the thin-film transistor, and the equivalent aperture ratio can be accordingly improved.
In prior art, less fabrication processes are used (e.g. the organic transparent layer is saved) in order to reduce the cost for manufacturing the foregoing lower substrate. This, however, results in that the pixel electrode has to be avoided from being formed over the thin-film transistor so as to prevent the increase of the stray capacitance and prevent the pixel electrode from affecting the electricity of the thin-film transistor.
However, when the electrophoretic display operates, charging particles inside the electrophoretic display are mainly driven by an electric field formed between the pixel electrode of the lower substrate and a thin-film transparent electrode of an upper substrate. Thus, if the pixel electrode has to be avoided from being formed over the thin-film transistor, the effective area for driving the charging particles between the upper electrode and the lower electrode will thus become decreased, resulting in that the electric field becomes weakened and cannot effectively drive the charging particles inside the electrophoretic display. As a result, the quality of displayed images will deteriorate.